Mosses Wood Road has been shut to traffic and pedestrians since before Christmas when prolonged rainfall caused the asphalt to buckle and the road dropped up to 5ft in places.

This week the head National Trust warden for the area, Rob Hewer, said there were fresh movements above the aptly named landslip car park. But it also looked as though the problem was now spreading down the slope to Broomehall Road. "All the indications are that the land is still moving," he said on Wednesday.

"Bumps have started to appear in Broomehall Road and the problem appears to be slowly creeping along. "There is very little we can do at the moment apart from monitor the situation closely with highways officials from the county council.

"Dozens of trees have come down and others are leaning over badly. We really won't be able to assess the situation until the spring at the earliest." A further worry for the head warden and his team is that sightseers are ignoring warning signs to keep away and turning up in droves to look at the devastation. "There are now concrete bollards in the road to prevent traffic from approaching but pedestrians are getting through," he added.

"People have been walking all over the place but it is very dangerous. The other day a man was standing above the landslip having his photo taken by his girlfriend. The top of the hill is fine but elsewhere it is very dodgy indeed."

The café by the tower has reported a significant drop in the number of visitors. Anyone planning a visit is advised not to approach the hill from Coldharbour. They should either leave their vehicles in the Windy Gap car park at the Ockley end of the road or in the Starveal car park near Abinger Common to the North. The damage to Mosses Wood Road has raised the question of whether or not it will ever reopen. Repairs will be hugely expensive and there is no guarantee that further slippage won't occur the next time there is a prolonged rainy spell. A previous major incident was recorded in 1866.

A spokesman for county highways department based at Pippbrook, Dorking, confirmed this week that a team of experts was monitoring the situation twice a week. She said a meeting had been held with local residents, parish councillors and other officials and a statement would be issued, probably next week. Until then the department was not prepared to comment.